ABSTRACTThe volumes of over 900 debris-flow deposits are compared. There is no definite relationship between magnitude and frequency, although small-scale flows occur more frequently than large-scale ones. The proportion of work done by relatively rare events varies from site to site. There are major differences in the volumes of debris flows in Scotland and Norway, Norwegian flows being an order of magnitude larger. The debris flows described here are most appropriately termed‘infrequent events’, the existing magnitude-frequency terminology being inadequate.